WASHINGTON — With tens of thousands of jobs, more than $1 billion and their reputations on the line, Senate Democrats gave way Friday to a power play by House Republicans in order to end a partial two-week shutdown of the Federal Aviation Administration.

With lawmakers scattered for Congress’ August recess, the consent of only two senators was required to pass a bill restoring the FAA’s operating authority through Sept. 16. President Barack Obama signed it into law hours later. But partisan differences remain, and a repeat performance of the legislative standoff could come next month.

The impasse had left hundreds of airport construction projects in limbo and idled tens of thousands of construction industry workers as well as nearly 4,000 FAA employees.

Story continues below advertisement.

One of the biggest costs was to the hard-pressed U.S. treasury, which lost about $400 million in uncollected taxes during the two-week standoff and stood to continue losing $30 million a day — more than $1 billion in total — if there had been no solution before Congress returns from its recess.

For most of the stalemate, the nation’s attention — and that of Congress — was riveted on the debt crisis finally tackled this week.

But that quickly shifted. Lawmakers were getting calls about unfinished airport towers and construction companies in dire straits at home. Some unemployed workers found their way to Capitol Hill to complain.

Democrats had been holding firm against the House legislation on FAA operations because it proposed cutting air service subsidies to 13 rural communities. In short, they feared getting steamrolled on similar legislation in the future if they gave Republicans their way. For example, spending authority for federal highway programs expires Sept. 30, another possible point of contention.

But once the focus fell away from the deal to avert a federal debt default, Democrats began to waver and finally gave up the fight.

Republicans achieved the subsidy cuts in the final law but with a major caveat. Transportation Secretary Ray LaHood has the authority to continue subsidized service to the 13 communities if he decides it’s necessary.

Obama’s signature means the nearly 4,000 furloughed FAA employees can return to work as soon as Monday. Work can also resume on more than 200 airport construction projects.

“This impasse was an unnecessary strain on local economies across the country at a time when we can’t allow politics to get in the way of our economic recovery,” Obama said in a statement.

Republican Rep. Tom Price of Georgia, chairman of the House Republican Policy Committee, said the FAA partial shutdown was “emblematic of the type of inaction and politics-come-first attitude we have seen from Senate Democrats all year.”

Bill Samuel, the AFL-CIO’s legislative director, saw the dispute differently. He said Republicans were willing to keep pushing their agenda at the expense of jobs and air safety.

“I think they’re getting reckless,” Samuel said in an interview. “Maybe with each victory they decide they can push a little farther.”

With the standoff on the nation’s radar screen so briefly, it’s hard to know whether either party will suffer political damage, said Norman Ornstein, an expert on Congress with the American Enterprise Institute. It could end up as another example of the public declaring a pox on both their houses.

“Voters hate this stuff,” he said. “They hate the damage … the dysfunction.”

Both the House and Senate passed long-term financing bills for the FAA earlier this year, but negotiations on resolving differences and completing the legislation remain stalled. That’s what made a short-term extension of spending authority necessary.

The agency has been operating under a series of 20 such extensions since 2007, when the last long-term FAA financing bill expired.

The biggest holdup is a labor provision in the House bill. Republicans want to overturn a National Mediation Board rule approved last year that allows airline and railroad employees to form a union by a simple majority of those voting. Under the old rule, workers who didn’t vote were treated as “no” votes.

Airline passengers in the busy travel season hardly noticed any of the changes over the two weeks.

Airlines continued to work as normal, but were no longer authorized to collect federal ticket taxes. For a few lucky ticket buyers, prices dropped. But for most, nothing changed because airlines raised their base prices to match the tax.